To be honest, I do share anchorhold's passion for military-style growbags, and for some aeroplane flying what he describes is extremely close to what I do in my own flying.
However, frankly I'm going to struggle in most flying environments to insist somebody wears one (I don't, more's the pity, teach on a Tiger Moth - nor at the moment anything else open cockpit or aerobatic). And even if I could, not unlike my earlier point about personal avionics - people will "do their own thing" once I'm not around. So, the only sensible approach, surely, is one that the student can be made to accept and believe is the way to manage their cockpit going forwards.
G